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Comment by wa1987 | Hacker News Reader

wa1987·

> On a Mac, there is a major performance hit whenever you do disk IO in a bind mount (i.e. voluming a directory of the host system into the container). Working without bind mounts is extremely limiting. [..] If you’re using Docker on a Mac and you’ve never tried it on Linux, you owe it to yourself to try it on Linux.

Or use named volumes. I'm running a dockerized WordPress dev environment on my MacBook with average TTFB's of 40 ms.

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I had to investigate why our docker-ized dev environment was so slow on macOS at my last job and this was the root cause. One project's test suite ran in about 5-10 mins in our linux CI/CD environment, and about 50+ mins in macOS with docker.

There was a very in-depth thread on the docker forums where the devs explained why there was such a huge performance penalty. IIRC it was due to all the extra bookkeeping that had to be done to ensure strong consistency and correct propagation of file system events between the virtualized docker for mac environment and the host file system.

The test suite would run integration tests that performed a lot of npm/yarn operations which meant lots of disk IO.

The reason is that docker on mac runs in a Linux VM and VM mounts are slow.

> Or use named volumes

And how do you access these from your host with high performant IO?

There’s no need to in my situation. 99% of the files are dependencies installed through Composer (PHP) while building the Dockerfile. The few directories I need to work on directly are bind mounts and don’t have much impact on overall runtime performance.

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